Angeles City (Philippines) (AFP) - Rescuers using thermal scanners pursued a search for survivors on Monday, a day after the collapse of a building under construction that has already claimed four lives, authorities said.

More than a dozen people are believed to be still missing after rescuers failed to bring out alive two trapped construction workers who had been found buried beneath the rubble in the northern city of Angeles on Sunday.

“We have detected signs of life” among the ruins, Maria Leah Sajiri, the regional spokeswoman for the fire bureau, told reporters.

“Rescue operations are ongoing,” she added.

The rescuers, led by local firemen, said they are using infrared technology to detect human body heat beneath the rubble.

Earlier Monday, two workers who were found alive and pinned beneath the wreckage of the nine-storey structure, later died despite rescue efforts.

“The first of the two was pulled out alive, but unfortunately, his body gave out and he did not survive. Doctors could not resuscitate him,” regional Sajili told AFP.

“The other one suffered a cardiac arrest around 3:00 am (1900 GMT Sunday). Doctors could not attend to him as he was still pinned down,” she added.

A Malaysian guest at a nearby hotel damaged by the collapsed building was also killed Sunday, while crews pulled another corpse from the rubble on Monday.

It was not immediately clear if the unidentified body belonged to a person listed among the missing, rescuers said in an updated toll.

Due to the uncertainty, authorities said approximately 17 other people were still considered missing, mostly construction workers who were sleeping at the building site when disaster struck.

Lea Casilao, girlfriend of a missing construction worker, told AFP she had taken a bus from her northern Manila home to Angeles with rice and canned goods for her partner on Sunday, unaware of the pre-dawn accident on the same day.

“It’s very difficult; it is breaking my heart to wait for something uncertain,” 47-year-old Casilao said, crying as she recounted how she slept alone at a local government building overnight Sunday.

- Lacking safety gear -

The cause of the collapse is not known.

Regional labour department director Geraldine Panlilio said she had briefly shut the project down in September 2024 over violations of occupational safety standards.

“Our labour inspectors had monitored poor working conditions, a violation that would put our workers at risk,” she said in an interview over Manila radio station DZMM.

The construction workers “lacked safety gear” like hardhats, boots, safety belts and lifelines, and worked under poor lighting and with no visible safety signage, she added.

Construction resumed a month later after the building contractor complied with requirements, Panlilio said.

Officials said up to 70 people were employed at the construction site, though most had gone home for the weekend.

Alfredo Albis, 55, told AFP he was asleep at a barracks for workers about five metres (16 feet) from the structure when it gave way.

“I have two cousins who are still trapped there. They were working here to earn for their families and (they) are missing,” he said, adding “there’s a possibility that my relatives are dead”.

Sajili, the fire bureau spokeswoman, said that “rescue in (a) building collapse is very challenging since any sudden shift triggered by the movements of our rescuers can cause areas to move and people under can get crushed”.

If no more survivors are found via scanners, earthmoving equipment will be brought in to clear debris and recover bodies, she said, but gave no timeline.